Focus control apparatus, focus control method, camera
apparatus and focus control method in camera apparatus

ABSTRACT

There is provided a focus control apparatus including: a first adjustment unit configured to adjust a focus distance; a second adjustment unit configured to adjust an addition amount of the focus distance adjusted with the first adjustment unit; and a focus control unit configured to control a focus based on the focus distance adjusted with the first adjustment unit and the addition amount adjusted with the second adjustment unit. Also provided are a focus control method, a camera apparatus and a focus control method in the camera apparatus.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Japanese Priority PatentApplication JP 2014-007468 filed Jan. 20, 2014, the entire contents ofwhich are incorporated herein by reference.

BACKGROUND

The present technology relates to a focus control apparatus, a focuscontrol method, a camera apparatus and a focus control method in thecamera apparatus. More particularly, the present technology relates to afocus control apparatus etc. that adjust a focus distance using a focusdemand, for example.

SUMMARY

In a cinema camera operation, there is a dedicated focus operator mainlyadjusting a focus as well as a camera operator doing a camera work. Thisframework is called as a follow focus. In a broadcasting operationincluding a live show, the camera operator should do a camera work and abasic focus work at the same time.

In the related art, a high-definition camera such as 4K is known (seeJapanese Patent Application Laid-open No. 2012-244411, for example). Asa captured image has a much higher definition, an accuracy for a focusdistance adjustment has been highly demanded. The camera operatoroperates based on a video picture in a view finder. A screen size islimited. Therefore, the camera operator focuses in detail withdifficulty while doing a camera frame work.

In addition, as a lens for 35 mm size image sensor has a depth fieldshallower than a lens for ⅔ inch size image sensor, a wide subjectcannot be focused. In other words, the screen has in-focused and out-offocus areas. When a will of the camera operation is mismatched with amotive of the director about a focus point within the screen, thesubject to be intended is not focused.

In view of the circumstances as described above, there is a need forproviding a good focus control.

According to an embodiment of the present technology, there is provideda focus control apparatus, including:

a first adjustment unit configured to adjust a focus distance;

a second adjustment unit configured to adjust an addition amount of thefocus distance adjusted with the first adjustment unit; and

a focus control unit configured to control a focus based on the focusdistance adjusted with the first adjustment unit and the addition amountadjusted with the second adjustment unit.

According to an embodiment of the present technology, the firstadjustment unit adjusts the focus distance. The second adjustment unitadjusts an addition amount of the focus distance adjusted with the firstadjustment unit. The focus control unit controls a focus based on thefocus distance adjusted with the first adjustment unit and the additionamount adjusted with the second adjustment unit.

According to an embodiment of the present technology, the focus iscontrolled based on the focus distance adjusted with the firstadjustment unit and the addition amount adjusted with the secondadjustment unit. A focus status adjusted with the first adjustment unitcan be finely adjusted with the second adjustment unit.

According to an embodiment of the present technology, the focus controlunit may use an absolute value of the addition amount adjusted with thesecond adjustment unit by reducing the absolute value of the additionamount depending on a change amount of the focus distance adjusted withthe first adjustment unit. In this case, when a status of capturing animage is changed and the focus distance adjusted with the firstadjustment unit is greatly changed, the absolute value of the additionamount adjusted with the second adjustment unit will be automaticallyreduced. Therefore, it is possible to automatically lessen the effect ofthe addition amount.

According to an embodiment of the present technology, the focus controlapparatus may further include a display control unit configured todisplay a status of the addition amount used in the focus control unit.In this case, the camera operator can easily know the current status ofthe addition amount.

According to an embodiment of the present technology, the firstadjustment unit may be a focus demand connected to the lens apparatus,and the second adjustment unit may be a follow focus controllerconnected to a camera control unit. In this case, the focus distanceadjusted with the focus demand by the camera operator can be finelyadjusted with the follow focus controller by the director.

In this case, the focus control apparatus may further includes a displaycontrol unit configured to display a screen area where the additionamount is adjusted with the follow focus controller on a view finderbased on screen area information transmitted from the camera controlunit. For example, the camera control unit may have a cutout function,and the screen area where the addition amount is adjusted may be acutout area. This allows the camera operator to easily know the screenarea where the addition amount is adjusted.

According to another embodiment of the present technology, there isprovided a camera apparatus, including:

a focus adjustment value generation unit configured to generate a focusadjustment value from a focus distance adjusted with a first adjustmentunit and an addition amount adjusted with a second adjustment unit tothe focus distance adjusted with the first adjustment unit; and

a focus control unit configured to control a focus based on the focusadjustment value generated in the focus adjustment value generationunit.

According to an embodiment of the present technology, the focusadjustment value is generated from the focus distance adjusted with thefirst adjustment unit and the addition amount adjusted with a secondadjustment unit to the focus distance adjusted with the first adjustmentunit. For example, the first adjustment unit may be a focus demandconnected to the lens apparatus, and the second adjustment unit may be afollow focus controller connected to a camera control unit. The focuscontrol unit controls the focus based on the focus adjustment valuegenerated in the focus adjustment value generation unit.

According to an embodiment of the present technology, the focus iscontrolled based on the focus distance adjusted with the firstadjustment unit and the addition amount adjusted with the secondadjustment unit, whereby the focus status adjusted with first adjustmentunit can be finely adjusted with the second adjustment unit.

According to an embodiment of the present technology, the focusadjustment value generation unit may use an absolute value of theaddition amount adjusted with the second adjustment unit by reducing theabsolute value of the addition amount depending on a change amount ofthe focus distance adjusted with the first adjustment unit. In thiscase, when a status of capturing an image is changed and the focusdistance adjusted with the first adjustment unit is greatly changed, theabsolute value of the addition amount adjusted with the secondadjustment unit will be automatically reduced. Therefore, it is possibleto automatically lessen the effect of the addition amount.

According to an embodiment of the present technology, the cameraapparatus may further includes a display control unit configured todisplay a status of the addition amount in the focus adjustment valuegenerated in the focus adjustment value generation unit on a viewfinder. In this case, the camera operator can easily the current statusof the addition amount.

According to an embodiment of the present technology, the cameraapparatus may further includes a display control unit configured todisplay a screen area where the addition amount is adjusted with thefollow focus controller on a view finder based on screen areainformation transmitted from the camera control unit. In this case, thecamera operator can easily know the focus adjustment position in thefollow focus controller. Accordingly, a focusing area can be easilyshared by the camera operator and a director.

According to an embodiment of the present technology, the focus can becontrolled successfully. Advantages described in the specification areonly illustrative and are not limited thereto, and additional advantagesmay be provided.

These and other objects, features and advantages of the presenttechnology will become more apparent in light of the following detaileddescription of best mode embodiments thereof, as illustrated in theaccompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing a configuration embodiment of a camerasystem according to a first embodiment of the present technology;

FIGS. 2A, 2B, 2C and 2D each is a diagram for illustrating a specificgenerating embodiment of a focus adjustment value in a camera CPU;

FIGS. 3A, 3B, 3C and 3D each is a diagram for illustrating a specificgenerating embodiment of a focus adjustment value in a camera CPU;

FIG. 4 is a block diagram showing a configuration embodiment of a camerasystem according to a second embodiment of the present technology.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present technology will be describedwith reference to the drawings.

The embodiments of the present technology will be described in thefollowing order.

1. First Embodiment 2. Second Embodiment 3. Alternative Embodiment 1.First Embodiment Configuration Embodiment of Camera System

FIG. 1 shows a configuration embodiment of a camera system 10 as a firstembodiment. The camera system 10 is composed of a camera apparatus 100and a camera control unit (CCU) 500 connected to the camera apparatus100 via a cable 600.

To the camera apparatus 100, a lens apparatus 200 and a view finder 300are connected. The lens apparatus 200 is mounted to a lens mount unit ata front of the camera apparatus 100. The lens apparatus 200 isconfigured to adjust the focus by a focus demand (focus controller) 400as well as by a follow focus controller 800 from a CCU 500 side.

The lens apparatus 200 includes a lens CPU 201 controlling operations ofthe respective units. The lens CPU 201 controls the focus based on afocus adjustment signal transmitted through a cable 202 from the CPU 101of the camera apparatus 100. In this case, the camera CPU 101 generatesa focus adjustment value from a focus distance adjusted with the focusdemand 400 and an addition amount adjusted with the follow focuscontroller 800 at the CCU 500 side.

In this case, the camera CPU 101 uses the absolute value of the additionamount adjusted with the follow focus controller 800 by reducing theabsolute value of the addition amount depending on a change amount ofthe focus distance adjusted with the focus demand 400. A specificgeneration embodiment of the focus adjustment value in the camera CPU101 will be described later.

The camera apparatus 100 includes the camera CPU 101, a user operationunit 102, a sensor unit 103, a camera signal processing unit 104 and aVF signal processing unit 105. The camera CPU 101 controls theoperations of the respective units in the camera apparatus 100. Thecamera CPU 101 establishes a necessary signal communication with thelens CPU 201 of the lens apparatus 200 and the CPU 501 of the CCU 500.The user operation unit 102 is connected to the camera CPU 101 andconfigures a user interface for a variety of operations by a user.

The sensor unit 103 includes a high-definition (high-resolution) imagesensor such as 4K or 8K and outputs a high-definition captured imagesignal corresponding to a subject. The above-described lens apparatus200 forms an image of the subject on an image capturing surface of theimage sensor. The camera signal processing unit 104 processes thecaptured image signal outputted from the sensor unit 103 and outputs animage signal (camera video signal) as an output from the cameraapparatus 100. The camera signal processing unit 104 performs processingincluding a gain control, a white balance adjustment and a gammacorrection.

The VF signal processing unit 105 generates an image signal having an HDresolution for the view finder based on the image signal outputted fromthe camera signal processing unit 104 and transmits the image signal tothe view finder 300. The VF signal processing unit 105 generates adisplay signal such as a display 301 showing a status of the additionamount in the focus adjustment value generated in the camera CPU 101based on a display control signal transmitted from the camera CPU 101,for example. Then, the VF signal processing unit 105 synthesizes thedisplay signal to the image signal (captured image signal) outputtedfrom the camera signal processing unit 104 and generates an image signalfor the view finder.

For example, the status of the addition amount shows that the additionamount has a “positive value” or a “negative value”. In FIG. 1, as anarrow from a base line (horizontal line) faces downward, it shows thatthe addition amount has the “negative value”. A length of the arrowshows a magnitude of the addition amount. In this case, when theaddition amount is zero, only the base line (horizontal line) isdisplayed and no arrow is displayed.

The CCU 500 includes the CPU 501, a user operation unit 502 and a videoprocessing unit 503. The CPU 501 controls the operation of therespective units of the CCU 500. The CPU 501 establishes a necessarysignal communication with the camera CPU 101 of the camera apparatus100. The user operation unit 502 is connected to the CPU 501 andconfigures the user interface for a variety of the operations by theuser.

The video processing unit 503 processes a high-definition image signalsuch as 4K or 8K transmitted through the cable 600 from the cameraapparatus 100 and outputs a high-definition image signal afterprocessing. A content of the high-definition image signal can beidentified on a large size monitor 510 corresponding to thehigh-definition image signal, for example.

Also, the follow focus controller 800 is connected to the CPU 501 via acable 801. When the user operates the follow focus controller 800, theaddition amount can be adjusted to the focus distance adjusted with thefocus demand 400. In this case, the user can adjust the addition amountin both positive and negative directions. The adjustment signal of theaddition amount is provided from the CPU 501 to the camera CPU 101 ofthe camera apparatus 100.

[Specific Generation Embodiment of Focus Adjustment Value]

Next, a specific generating embodiment of a focus adjustment value inthe camera CPU 101 will be described referring to FIGS. 2 and 3. InFIGS. 2 and 3, a “D-FP” represents the focus adjustment value (focusdistance) adjusted with the focus demand 400, a “F-FP” represents theaddition amount by the follow focus controller 800, and “R-FP”represents the focus adjustment value (actual focus adjustment value)generated in the camera CPU 101.

This embodiment shows that an absolute value of the addition amountadjusted with the follow focus controller 800 is reduced by ⅓ of anabsolute value of a variable amount of the focus adjustment valueadjusted with the focus demand 400. In this embodiment, a ratio of “⅓”is used. Other ratios can be used although the detailed description isomitted.

The focus adjustment values are generated as shown in FIG. 2. As shownin FIG. 2A, it is assumed that the focus adjustment value “D-FP”adjusted with the focus demand 400 by a camera operator is “53”. At thistime, the camera CPU 101 set the focus adjustment value “R-FP” to “53”.Here, it is assumed that the range of the focus adjustment value is 0 to99.

The focus adjustment value “R-FP” of “53” is not in a status that atarget subject is in focus. As shown in FIG. 22, it is assumed that afollow focus operator finely adjusts the focus by the follow focuscontroller 800 and the addition amount “F-FP” is “+5”. At this time,while the focus adjustment value “D-FP” adjusted with the focus demand400 is still “53”, the camera CPU 101 sets the focus adjustment value“R-FP” to “58” by adding “+5”.

From this point, the camera operation pans to adjust the focus by thefocus demand 400 to match an image capturing position. As shown in FIG.2C, when the focus adjustment value “D-FP” is “44”, the camera CPU 101reduces the absolute value of the addition amount “F-FP” by “3” that is⅓ of the absolute value of the variable amount of the focus adjustmentvalue “9” and sets the addition amount “F-FP” to “+2” and the focusadjustment value “R-FP” to “46”. Accordingly, the change amount of thefocus adjustment value “R-FP” in this case will be “−12”.

From this point, the camera operation pans again to adjust the focus bythe focus demand 400 to match an image capturing position. As shown inFIG. 2D, when the focus adjustment value “D-FP” is “38”, the camera CPU101 reduces the absolute value of the addition amount “F-FP” by “2” thatis ⅓ of the absolute value of the variable amount of the focusadjustment value “6” and sets the addition amount “F-FP” to “0” and thefocus adjustment value “R-FP” to “38”. Accordingly, the change amount ofthe focus adjustment value “R-FP” in this case will be “−8”.

Next, the focus adjustment values are generated as shown in FIG. 3. Asshown in FIG. 3A, it is assumed that the focus adjustment value “D-FP”adjusted with the focus demand 400 by a camera operator is “53”. At thistime, the camera CPU 101 set the focus adjustment value “R-FP” to “53”.Here, it is assumed that the range of the focus adjustment value is 0 to99.

The focus adjustment value “R-FP” of “53” is not in a status that atarget subject is in focus. As shown in FIG. 3B, it is assumed that afollow focus operator finely adjusts the focus by the follow focuscontroller 800 and the addition amount “F-FP” is “+5”. At this time,while the focus adjustment value “D-FP” adjusted with the focus demand400 is still “53”, the camera CPU 101 sets the focus adjustment value“R-FP” to “58” by adding “+5”.

From this point, the camera operation pans to adjust the focus by thefocus demand 400 to match an image capturing position. As shown in FIG.3C, when the focus adjustment value “D-FP” is “59”, the camera CPU 101reduces the absolute value of the addition amount “F-FP” by “2” that is⅓ of the absolute value of the variable amount of the focus adjustmentvalue “6” and sets the addition amount “F-FP” to “+3” and the focusadjustment value “R-FP” to “62”. Accordingly, the change amount of thefocus adjustment value “R-FP” in this case will be “+4”.

From this point, the camera operation pans again to adjust the focus bythe focus demand 400 to match an image capturing position. As shown inFIG. 3D, when the focus adjustment value “D-FP” is “68”, the camera CPU101 reduces the absolute value of the addition amount “F-FP” by “3” thatis ⅓ of the absolute value of the variable amount of the focusadjustment value “9” and sets the addition amount “F-FP” to “0” and thefocus adjustment value “R-FP” to “68”. Accordingly, the change amount ofthe focus adjustment value “R-FP” in this case will be “+6”.

Although not described above, it is contemplated that the value of thefocus adjustment value “D-FP” added to the addition amount “F-FP”exceeds the range of the focus adjustment value, e.g., 0 to 99 dependingon the focus adjustment value “D-FP” adjusted with the focus demand 400or the addition amount “F-FP” adjusted with the follow focus controller800. In this case, the camera CPU 101 generates the focus adjustmentvalues by reducing the absolute value of the addition amount “F-FP” suchthat an actual focus adjustment value “R-FP” does not exceed the rangeof the focus adjustment value.

Also, although not described above, a magnitude (maximum amplitude) ofthe addition amount “F-FP” adjusted with the follow focus controller 800may be set. In this case, the addition amount “F-FP” can be limited andthe focus adjustment by the follow focus controller 800 can be limitedto a fine adjustment.

As described above, in the camera system 10 shown in FIG. 1, the focuscontrol is performed based on the focus adjustment value adjusted withthe focus demand 400 and the addition amount adjusted with the followfocus controller 800. Therefore, a focus status adjusted with the focusdemand 400 can be finely adjusted with the follow focus controller 800.

In addition, in the camera system 10 shown in FIG. 1, the camera CPU 101uses the absolute value of the addition amount adjusted with the followfocus controller 800 by reducing the absolute value of the additionamount depending on a change amount of the focus distance adjusted withthe focus demand 400. Accordingly, when a status of capturing an imageis changed once the camera operator pans and the focus distance adjustedwith the focus demand 400 is greatly changed, the absolute value of theaddition amount adjusted with the follow focus controller 800 will beautomatically reduced. Therefore, it is possible to automatically lessenthe effect of the addition amount that is not or less related to thestatus of capturing the image after change.

In the camera system 10 shown in FIG. 1, the VF signal processing unit105 generates a display signal such as a display 301 showing the statusof the addition amount in the focus adjustment value generated in thecamera CPU 101, synthesizes the display signal to the image signal(captured image signal) outputted from the camera signal processing unit104 and generates an image signal for the view finder. Therefore, thecamera operator can easily know the current status of the additionamount, for example.

2. Second Embodiment Configuration Embodiment of Camera System

FIG. 4 shows a configuration embodiment of a camera system 10A accordingto a second embodiment of the present technology. The camera system 10Aincludes a camera apparatus 100A and a camera control unit (CCU) 500Aconnected to the camera apparatus 100A via a cable 600. In FIG. 4, thecomponents already described are denoted by the same reference numerals,and thus detailed description thereof will be hereinafter omitted.

To the camera apparatus 100A, the lens apparatus 200 and the view finder300 are connected. The camera apparatus 100A includes the camera CPU101, the user operation unit 102, the sensor unit 103, the camera signalprocessing unit 104 and the VF signal processing unit 105. The VF signalprocessing unit 105A generates an image signal having an HD resolutionfor the view finder based on the image signal outputted from the camerasignal processing unit 104 and transmits the image signal to the viewfinder 300.

The VF signal processing unit 105A generates a display signal such as adisplay 301 showing a status of the addition amount in the focusadjustment value generated in the camera CPU 101 based on a displaycontrol signal transmitted from the camera CPU 101 and a rectangularframe display 302 showing a cutout position (area) in the CCU 500A. Therectangular frame display 302 shows a screen area where the additionamount is adjusted with the follow focus controller 800, as describedlater.

The CCU 500A includes the CPU 501, the user operation unit 502, thevideo processing unit 503, and a cutout processing unit 504. The cutoutprocessing unit 504 takes out and outputs an image signal having an HDresolution at the cutout position (area) from a high-definition imagesignal provided by the video processing unit 503. The cutout position(area) is acknowledged through a cable 701 from a cutout controller 700by the CPU 501.

A user can change the cutout position (area) to any position byoperating the cutout controller 700. A large size monitor 510 displays acontent of the high-definition image signal provided by the videoprocessing unit 503. The image is subjected to a rectangular framedisplay 511 showing the cutout position (area). The user can refer therectangular frame display 511 and move the cutout position (area) to anappropriate position.

To the CPU 501, the follow focus controller 800 is connected via thecable 801. The user operates the follow focus controller 800 to adjustthe addition amount of the focus distance adjusted with the focus demand400 and performs the focus adjustment (fine adjustment) of the cutoutposition (area). In this case, the user can adjust the addition amountin both positive and negative directions. The adjustment signal of theaddition amount is provided to the camera CPU 101 of the cameraapparatus 100.

Although no description is provided in detail, others of the camerasystem 10A shown in FIG. 4 are configured as those of the camera system10 shown in FIG. 1. The camera system 10A shown in FIG. 4 can providethe function effects similar to those of the camera system 10 shown inFIG. 1.

In addition, in the camera system 10A shown in FIG. 4, the VF signalprocessing unit 105A generates a display signal such as the rectangularframe display 302 showing a focus adjustment position (the cutoutposition (area)) in the follow focus controller 800, synthesizes thedisplay signal to the image signal (captured image signal) outputtedfrom the camera signal processing unit 104 and generates an image signalfor the view finder. Therefore, the camera operator can easily know thefocus adjustment position in the follow focus controller 800.Accordingly, a focusing area can be shared by the camera operator and adirector.

3. Alternative Embodiment

In the above-described embodiments, the focus distance adjusted with thefocus demand 400 connected to the lens apparatus 200 is finely adjustedwith the follow focus controller 800 connected to the CCU 500, 500A.However, it should be appreciated that the present technology is notlimited to and the present technology can be applied to theconfiguration that the focus distance adjusted with a first adjustmentunit can be finely adjusted with a second adjustment unit.

The present technology may have the following configurations.

(1) A focus control apparatus, including:

a first adjustment unit configured to adjust a focus distance;

a second adjustment unit configured to adjust an addition amount of thefocus distance adjusted with the first adjustment unit; and

a focus control unit configured to control a focus based on the focusdistance adjusted with the first adjustment unit and the addition amountadjusted with the second adjustment unit.

(2) The focus control apparatus according to (1) above, in which

the focus control unit uses an absolute value of the addition amountadjusted with the second adjustment unit by reducing the absolute valueof the addition amount depending on a change amount of the focusdistance adjusted with the first adjustment unit.

(3) The focus control apparatus according to (1) or (2) above, furtherincluding:

a display control unit configured to display a status of the additionamount used in the focus control unit.

(4) The focus control apparatus according to any one of (1) to (3)above, in which

the first adjustment unit is a focus demand connected to the lensapparatus, and

the second adjustment unit is a follow focus controller connected to acamera control unit.

(5) The focus control apparatus according to (4) above, furtherincluding:

a display control unit configured to display a screen area where theaddition amount is adjusted with the follow focus controller on a viewfinder based on screen area information transmitted from the cameracontrol unit.

(6) The focus control apparatus according to (5) above, in which

the camera control unit has a cutout function, and

the screen area where the addition amount is adjusted is a cutout area.

(7) A method of controlling a focus, including:

adjusting a focus distance as a first adjustment step;

adjusting an addition amount of the focus distance adjusted with thefirst adjustment step as a second adjustment step; and

controlling a focus based on the focus distance adjusted with the firstadjustment step and the addition amount adjusted with the secondadjustment step.

(8) A camera apparatus, including:

a focus adjustment value generation unit configured to generate a focusadjustment value from a focus distance adjusted with a first adjustmentunit and an addition amount adjusted with a second adjustment unit tothe focus distance adjusted with the first adjustment unit; and

a focus control unit configured to control a focus based on the focusadjustment value generated in the focus adjustment value generationunit.

(9) The camera apparatus according to (8) above, in which

the focus adjustment value generation unit uses an absolute value of theaddition amount adjusted with the second adjustment unit by reducing theabsolute value of the addition amount depending on a change amount ofthe focus distance adjusted with the first adjustment unit.

(10) The camera apparatus according to (9) above, further including:

a display control unit configured to display a status of the additionamount in the focus adjustment value generated in the focus adjustmentvalue generation unit.

(11) The camera apparatus according to (9) or (10) above, in which

the first adjustment unit is a focus demand connected to the lensapparatus, and

the second adjustment unit is a follow focus controller connected to acamera control unit.

(12) The camera apparatus according to any one of (9) to (11) above,further including:

a display control unit configured to display a screen area where theaddition amount is adjusted with the follow focus controller on a viewfinder based on screen area information transmitted from the cameracontrol unit.

(13) P method of controlling a focus in a camera apparatus, including:

generating a focus adjustment value from a focus distance adjusted witha first adjustment unit and an addition amount adjusted with a secondadjustment unit to the focus distance adjusted with the first adjustmentunit; and

controlling the focus by a focus control unit based on the focusadjustment value generated in the focus adjustment value generation.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

What is claimed is:
 1. A focus control apparatus, comprising: a firstadjustment unit configured to adjust a focus distance; a secondadjustment unit configured to adjust an addition amount of the focusdistance adjusted with the first adjustment unit; and a focus controlunit configured to control a focus based on the focus distance adjustedwith the first adjustment unit and the addition amount adjusted with thesecond adjustment unit.
 2. The focus control apparatus according toclaim 1, wherein the focus control unit uses an absolute value of theaddition amount adjusted with the second adjustment unit by reducing theabsolute value of the addition amount depending on a change amount ofthe focus distance adjusted with the first adjustment unit.
 3. The focuscontrol apparatus according to claim 1, further comprising: a displaycontrol unit configured to display a status of the addition amount usedin the focus control unit.
 4. The focus control apparatus according toclaim 1, wherein the first adjustment unit is a focus demand connectedto the lens apparatus, and the second adjustment unit is a follow focuscontroller connected to a camera control unit.
 5. The focus controlapparatus according to claim 4, further comprising: a display controlunit configured to display a screen area where the addition amount isadjusted with the follow focus controller on a view finder based onscreen area information transmitted from the camera control unit.
 6. Thefocus control apparatus according to claim 5, wherein the camera controlunit has a cutout function, and the screen area where the additionamount is adjusted is a cutout area.
 7. A method of controlling a focus,comprising: adjusting a focus distance as a first adjustment step;adjusting an addition amount of the focus distance adjusted with thefirst adjustment step as a second adjustment step; and controlling afocus based on the focus distance adjusted with the first adjustmentstep and the addition amount adjusted with the second adjustment step.8. A camera apparatus, comprising: a focus adjustment value generationunit configured to generate a focus adjustment value from a focusdistance adjusted with a first adjustment unit and an addition amountadjusted with a second adjustment unit to the focus distance adjustedwith the first adjustment unit; and a focus control unit configured tocontrol a focus based on the focus adjustment value generated in thefocus adjustment value generation unit.
 9. The camera apparatusaccording to claim 8, wherein the focus adjustment value generation unituses an absolute value of the addition amount adjusted with the secondadjustment unit by reducing the absolute value of the addition amountdepending on a change amount of the focus distance adjusted with thefirst adjustment unit.
 10. The camera apparatus according to claim 9,further comprising: a display control unit configured to display astatus of the addition amount in the focus adjustment value generated inthe focus adjustment value generation unit.
 11. The camera apparatusaccording to claim 9, wherein the first adjustment unit is a focusdemand connected to the lens apparatus, and the second adjustment unitis a follow focus controller connected to a camera control unit.
 12. Thecamera apparatus according to claim 9, further comprising: a displaycontrol unit configured to display a screen area where the additionamount is adjusted with the follow focus controller on a view finderbased on screen area information transmitted from the camera controlunit.
 13. A method of controlling a focus in a camera apparatus,comprising: generating a focus adjustment value from a focus distanceadjusted with a first adjustment unit and an addition amount adjustedwith a second adjustment unit to the focus distance adjusted with thefirst adjustment unit as a focus adjustment value generation step; andcontrolling the focus based on the focus adjustment value generated inthe focus adjustment value generation step as a focus control step.